1. Field of the Invention
The invention relates to new 3-hydroxy-3-(2-methyl-5-pyridyl)-propionic acid alkyl esters, a process for the production of such compounds and the use of such compounds for the production of 2-methylpyridine-5-propionic acid alkyl esters.
2. Prior Art
2-Methylpyridine-5-propionic acid alkyl esters are important intermediate products for a series of new histamine H.sub.1 and H.sub.2 antagonists [Drugs of the Future, 7, 157 (1982)].
3-Pyridine propionic acid ethyl esters have been produced in a yield of 92 percent by the hydrogenation of nicotinoyl acetate in the presence of a palladium/barium sulfate catalyst [Graef et al., J. Org. Chem., 11, 257, (1946)]. As the tests of the applicant herein prove, the reaction cannot be transferred to 6-methyl nicotinoyl acetate. Further, it is known to produce 2-methylpyridine-5-alkyl propionic acid alkyl ester starting from 6-methylpyridine-3-carbaldehyde by a three-stage synthesis (European Patent Application No. 0003677). But in such process, it is disadvantageous that the starting product, 6-methylpyridine-3-carbaldehyde, must be produced from 2-methyl-5-vinylpyridine that is difficult to obtain and is very expensive.